iOO NOVITATES ZoOLOaiCAE XXII. 1915. 



photographs, figs. 4 and 5. Fig. 2, acuta, has a very similar appearance, bnt here 

 the Jots are damages to the specimens, mnch more visible to the camera than to 

 the nnaided eye. 



The extent to which the black border invades the inner margin of the wing 

 varies a good deal. 



The appendages are on the same type as bulis ; they may be at once distin- 

 guished by the aedeagus being much shorter (2'0 mm.) ; the extremity, instead of 

 being square, has a pointed trowel-shaped form, and so looks much narrower ; and 

 instead of the long compound double row of very numerous small coruuti, it has 

 only a few of comparatively very large size. 



There are specimens of spertkis from Malacca, N.E. Sumatra, Java, and 

 Borneo. 



In mounting the abdomina of S specimens of Curetis my attention was at once 

 attracted by the existence of a fan on the basal abdominal segment, which I found 

 in all the examples of the genus in which I looked for it. It is very similar to the 

 fan that exists in Sphinges, and still more like that found in some Noctuae. I 

 am not aware that a similar abdominal fan has hitherto been described in any 

 butterfly. The fan consists of a large pencil of hairs arising from a special area on 

 the lower posterior angle of the dorsal plate of the second abdominal segment. 

 The hairs are rather more than 2-0 mm. long. No doubt, in use, they are spread 

 and displayed and probably diffuse a scent, but I have not met with any record of 

 their having been observed. At rest, they lie closely together in a special pocket, 

 which crosses obliquely the steruite of the third abdominal segment and encroaches 

 on the fourth. The precise disx'osition of the pockets will jierhaps be better 

 gathered from figs. 78 ( x 8), 79 and 80 ( x 15). In fig. 80, though all the hairs are 

 in the pocket, a number have been torn away from their point of origin. Fig. S3 

 shows the hairs and their origin ( x 25). Fig. 82 is similar, a number of the hairs 

 have been lost, but one side of the pocket separated from its attachments is seen. 



The scale sockets of the area about the pocket present the usual vase-like or 

 dumb-bell outline (fig. 84, x 300) ; passing from these to the pocket, they gradually 

 change their form, until in the pocket itself they have a flask-like, nearly globular 

 form, and give rise not to scales, but to short tapering hairs (fig. 85, x 300). 



It would seem that the sockets have been modified into scent glands, with a 

 certain capacity to accommodate an accumulation of the scent material, and that the 

 fine hairs served to conduct it to the hairs of the fan when about to be expanded. 



The hairs of the fan have no spicules, but are very straight and simple, yet 

 when highly magnified, have a spongy, corky look, not the smooth, polished 

 surface of most insect hairs, so that one supposes them to be somewhat spongy in 

 order to absorb a supply of scent. 



The well-known scent-fans of Sphinges much resemble these fans of Curetis, 

 but their disposition diff'ers somewhat; the fan or pencil of hairs in Sphinges arises 

 from the same segment, the second abdominal, not however from the tergite, but 

 from the middle of the dorsal margin of the sternitc ; the pocket in which it rests 

 is merely the fold of membrane between the dorsal and ventral plates. 



In a Koctna (an American Acontian is figured) the fan arises from the first 

 abdominal sternite, and occupies a pocket almost identical in appearance with that 

 in Curetis; the difference from Curetis is in the point of origin of the fan and in 

 the pocket being longitudinal instead of oblique; a photograph of a portion of this 

 preparation is shown in fig. 81. 



